1、 Reference number ISO/TR 12391-4:2002(E) ISO 2002TECHNICAL REPORT ISO/TR 12391-4 First edition 2002-12-15 Gas cylinders Refillable seamless steel Performance tests Part 4: Flawed-cylinder cycle test Bouteilles gaz Rechargeables en acier sans soudure Essais de performance Partie 4: Cycle dessai pour
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5、Secretariat at the address given below. ISO 2002 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at th
6、e address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2002 All rights reservedISO/TR 12391-4:2002(E) ISO 2002 All
7、 rights reserved iiiContents Page Foreword iv Introduction v 1 Scope 1 2 References. 1 3 Terms and definitions. 2 4 Symbols. 2 5 Background. 3 6 Experimental test programme . 4 6.1 Types of cylinder tested. 4 6.2 Material properties tests. 5 6.3 Description of the flawed-cylinder cycle test. 6 7 Fla
8、wed-cylinder cycle test results. 8 7.1 Flawed-cylinder cycle test procedure. 8 7.2 Flawed-cylinder cycle test results for group F-B materials 8 7.3 Flawed-cylinder cycle test results for group F-C materials 8 7.4 Flawed-cylinder cycle test results for group F-D materials 9 7.5 Flawed-cylinder cycle
9、test results for group F-E materials 10 8 Discussion. 10 8.1 Background. 10 8.2 Flawed-cylinder cycle test procedures and acceptance criteria (ISO 9809-2) 10 8.3 Pressure cycling tests (ISO 9809-2) 11 9 Conclusions. 11 ISO/TR 12391-4:2002(E) iv ISO 2002 All rights reservedForeword ISO (the Internati
10、onal Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been
11、 established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standa
12、rdization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for
13、voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the a
14、rt”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Attention is drawn t
15、o the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 12391-4 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 3, Cylinder design. ISO/TR 1
16、2391 consists of the following parts, under the general title Gas cylinders Refillable seamless steel Performance tests: Part 1: Philosophy, background and conclusions Part 2: Fracture performance tests Monotonic burst tests Part 3: Fracture performance tests Cyclical burst tests Part 4: Flawed-cyli
17、nder cycle test ISO/TR 12391-4:2002(E) ISO 2002 All rights reserved vIntroduction Gas cylinders as specified in ISO 9809-1 have been constructed of steel with a maximum tensile strength of less than 1 100 MPa. With the technical changes in steel-making using a two-stage process, referred to as ladle
18、 metallurgy or secondary refining, significant improvement in mechanical properties have been achieved. These improved mechanical properties provide the opportunity of producing gas cylinders with higher tensile strength, which achieve a lower ratio of steel to gas weight. The major concern in using
19、 steels of higher tensile strength with correspondingly higher design wall stress is safety throughout the life of the gas cylinder. When ISO/TC 58/SC 3 began drafting ISO 9809-2, Working Group 14 was formed to study the need for additional controls for the manufacture of steel gas cylinders having
20、a tensile strength greater than 1 100 MPa. This part of ISO/TR 12391 presents all of the specific test results of the flawed-cylinder cycle tests that were conducted to evaluate the fatigue performance of cylinders ranging in tensile strength from less 800 MPa to greater than 1 350 MPa. TECHNICAL RE
21、PORT ISO/TR 12391-4:2002(E) ISO 2002 All rights reserved 1Gas cylinders Refillable seamless steel Performance tests Part 4: Flawed-cylinder cycle test 1 Scope This part of ISO/TR 12391 applies to seamless steel refillable cylinders of all sizes from 0,5 l up to and including 150 l water capacity pro
22、duced of steel with tensile strength, R m , greater than 1 100 MPa. It can also be applied to cylinders produced from steels used at lower tensile strengths. In particular, it provides the technical rationale and background to guide future alterations of existing ISO standards or for developing adva
23、nced design standards. This part of ISO/TR 12391 is a summary and compilation of the test results obtained during the development of the “flawed-cylinder cycle test”. The “flawed-cylinder cycle test” was developed as part of a co-operative project under the direction of ISO/TC 58/SC 3/WG 14. The “fl
24、awed-cylinder cycle test” is a test method to evaluate the fatigue performance of steel cylinders that are used to transport high pressure, compressed gases. The concept and development of the flawed-cylinder cycle test is described in ISO/TR 12391-1. The details of the test method and the criteria
25、for acceptable fatigue performance of steel cylinders are given in 9.2.6 of ISO 9809-2:2000, “flawed-cylinder cycle test”. In this part of ISO/TR 12391, test results are reported for more than a hundred flawed-cylinder cycle tests that were conducted on seamless steel cylinders ranging in measured t
26、ensile strength from less than 800 MPa to greater than 1 350 MPa. The test method is intended to be used for the selection of materials and design parameters in the development of new cylinder designs. 2 References ISO 148:1983, Steel Charpy impact test (V-notch) ISO 6406: 1) , Seamless steel gas cy
27、linders Periodic inspection and testing ISO 9809-1:1999, Gas cylinders Refillable seamless steel gas cylinders Design, construction and testing Part 1: Quenched and tempered steel cylinders with tensile strength less than 1 100 MPa ISO 9809-2:2000, Gas cylinders Refillable seamless steel gas cylinde
28、rs Design, construction and testing Part 2: Quenched and tempered steel cylinders with tensile strength greater than or equal to 1 100 MPa ISO/TR 12391-1, Gas cylinders Refillable seamless steel Performance tests Part 1: Philosophy, background and conclusions 1) To be published. (Revision of ISO 640
29、6:1992) ISO/TR 12391-4:2002(E) 2 ISO 2002 All rights reservedISO/TR 12391-2, Gas cylinders Refillable seamless steel Performance tests Part 2: Fracture performance test Monotonic burst tests ISO/TR 12391-3, Gas cylinders Refillable seamless steel Performance tests Part 3: Fracture performance tests
30、Cyclical burst tests 3 Terms and definitions 3.1 flawed-cylinder cycle test test conducted on a finished gas cylinder having a shallow prescribed flaw of 10 % of the cylindrical wall thickness machined into the exterior sidewall and failed by cyclical internal pressurization that is normally hydraul
31、ic 3.2 flawed-cylinder burst test test conducted on a finished gas cylinder having a deep prescribed flaw in the range of 75 % of the cylindrical wall thickness machined into the exterior sidewall and failed by internal pressurization that may be hydraulic, and is applied either monotonically or cyc
32、lically 3.3 pressure cycling test test conducted on a finished gas cylinder that does not have a flaw machined into the exterior sidewall and failed by cyclical internal pressurization that is normally hydraulic 4 Symbols d is the flaw depth, expressed in millimetres as a percentage of t d ; D is th
33、e outside diameter of the cylinder, expressed in millimetres; l ois the flaw length, expressed in millimetres (= n t d ); n represents multiples of t d(= l o /t d ); P his the calculated design test pressure for the cylinder, expressed in bar; P sis the calculated design service pressure for the cyl
34、inder, expressed in bar; R eis the guaranteed minimum yield strength; R eais the actual measured value of yield strength, expressed in megapascals; R g, maxis the maximum value of tensile strength guaranteed by the manufacturer, expressed in megapascals; R g, minis the minimum value of tensile stren
35、gth guaranteed by the manufacturer, expressed in megapascals; R mis the actual measured value of tensile strength, expressed in megapascals; t ais the actual measured wall thickness at the location of the flaw, expressed in millimetres; t dis the calculated minimum design wall thickness, expressed i
36、n millimetres. ISO/TR 12391-4:2002(E) ISO 2002 All rights reserved 35 Background High-pressure industrial gases (such as oxygen, nitrogen, argon, hydrogen, helium, etc.) are stored and transported in portable steel cylinders. These cylinders are designed, manufactured, and maintained in accordance w
37、ith ISO 9809-1 and ISO 9809-2. The cylinders are constructed from specified alloy steels that generally contain chromium and molybdenum as the principal alloying elements. The cylinders are of seamless construction and are manufactured by either a forging process, a tube-drawing process or by a plat
38、e-drawing process. The required mechanical properties are obtained by using an austenitizing, quenching, and tempering heat treatment. Typical sizes of these cylinders are 100 mm to 250 mm in diameter, 500 mm to 2 000 mm in length, and 3 mm to 20 mm in wall thickness. Typical working pressure ranges
39、 are 100 bar to 400 bar. Until recently, the tensile strength of the steels used in the construction of such cylinders has been limited to a maximum of about 1 100 MPa. This limitation for the maximum tensile strength occurs because the fracture toughness and ductility of the steels decreases with i
40、ncrease in the tensile strength and above a tensile strength of about 1 100 MPa the fracture toughness and ductility were not adequate to prevent fracture of the cylinders. Recently developed new steel alloys that have both high tensile strength and high fracture toughness and ductility make it poss
41、ible to construct lighter cylinders with higher tensile strength steels. This permits the use of cylinder designs with higher permissible stresses in the cylinder wall increased for a constant wall thickness. The use of higher strength steels therefore leads to a lower ratio of steel weight to gas w
42、eight that reduces shipping and handling costs. A major concern in using higher strength steels for cylinder construction and correspondingly higher design wall stress is the ability to maintain the same level of safety throughout the life of the cylinder. In particular, increasing the tensile stren
43、gth of the steels and increasing the stress in the wall of the cylinders could make the cylinders less fracture resistant and more subject to fatigue failure than cylinders made from steels with the traditionally used lower tensile strength levels. In order to use steels with strength levels higher
44、than 1 100 MPa, it was decided that new requirements were needed to assure adequate fracture and fatigue resistance of the cylinders. To develop these requirements, WG 14 was formed under ISO/TC 58/SC 3. WG 14 was assigned the task: “develop a suitable test method and specifications to assure adequa
45、te fracture resistance for gas cylinders made from steels with tensile strengths greater than 1 100 MPa”. The results of the test programme to develop suitable test methods and acceptance criteria to ensure adequate fracture performance are described in ISO/TR 12391-1, ISO/TR 12391-2 and ISO/TR 1239
46、1-3. The original scope of the WG 14 work was amended to also include the development of a suitable test method and acceptance criteria to ensure adequate fatigue resistance for gas cylinders made from steels with tensile strengths greater than 1 100 MPa. This was required because the fatigue crack
47、growth rate is controlled by the wall stress in the cylinder, so that by increasing the tensile strength of the steels and increasing the stress in the wall of the cylinders the cylinders may become less fatigue resistant and more subject to fatigue failure than cylinders made from steels with the t
48、raditionally used lower tensile strength levels. WG 14 decided that the test method and acceptance criteria that were developed to evaluate the fatigue performance of the cylinders should demonstrate that the overall “fatigue resistance” of cylinders made from higher strength steels was equivalent t
49、o that of cylinders made from lower strength steels. It was decided that the test method that was developed should measure the total fatigue resistance of the cylinder and not just the fatigue crack growth rate of the steel used in the cylinder. Therefore, the test method that was developed to evaluate the total fatigue performance of cylinders was the “flawed-cylinder cycle test”. The concept of the flawed-cylinder cycle test and the development conducted under WG 14 is describe
